scholarly journals Experimental and Computational Investigation of Flow Fields using Accelerated Erosion Test Ring (AETR)

2021 ◽  
Author(s):  
Vineet Singh ◽  
◽  
Vinod Singh Yadav ◽  
Vinod Kumar Yadav ◽  
Niraj Kumar ◽  
...  
Keyword(s):  
Turbine Blades ◽  
Sand Particle ◽  
Computational Techniques ◽  
Centrifugal Pumps ◽  
Computational Investigation ◽  
Global Challenge ◽  
Hydraulic Machines ◽  
Erosion Test ◽  
Scientists And Engineers ◽  
Set Up

The erosion of the blades of hydraulic pumps and turbines, caused due to the water that has enormous suspended particles and erosive agents, is a severe global challenge among scientists and engineers. In the present work, an attempt has been made to compute the extent of erosion caused by water when it passes through devices like hydraulic machines, centrifugal pumps and turbines. Experimental and computational techniques using pitched turbine blades with 45o with the horizontal plane under down pumping condition is employed for investigation of the suspension phenomena for calculating erosion wear by sand suspended in water in river, canal on turbine, pump blades. An experimental set up, named as Accelerated Erosion Test Rig (AETR), is developed through dimensional analysis. For experimental analysis, the sand particle size and propeller dimensions were varied while running the propeller at different speeds. Experimental results revealed that the propeller speed must be maintained at an optimum value, preferably lower speeds, to ensure maximum lifting of impurities and sand particles from the base of the cylinder.

scholarly journals Using a roller pump for establishing extra-corporal membrane oxygenation (ECMO) – technical considerations for times of crisis

Perfusion ◽  
2021 ◽  
pp. 026765912199618
Author(s):  
Mirko Kaluza ◽  
Benjamin May ◽  
Torsten Doenst
Keyword(s):  
Flow Characteristics ◽  
Centrifugal Pumps ◽  
Roller Pump ◽  
Silicone Tubing ◽  
Heart Lung Machine ◽  
Surface Irregularities ◽  
Set Up ◽  
Flow Detection ◽  
Silicon Tubing

Objective: The COVID-19 pandemic requires thinking about alternatives to establish ECMO when often-limited hardware resources are exhausted. Heart-lung-machines may potentially be used for ECMO but contain roller pumps as compared to centrifugal pumps in ECMO-circuits. We here tested roller pumps as rescue pump for ECMO-establishment. Methods: We set up in vitro circuits on roller pumps from C5 heart-lung-machine with 5 l/minutes flow. In two series, we placed either PVC or silicon tubing for an ECMO circuit into the roller pump. We assessed the mechanical stress on the tubing (aiming to run the pump for at least 1 week), measured the temperature increase generated by the friction and assessed flow characteristics and its measurement in simulated situations resembling tube kinking and suction. Results: The roller pumps led to expected and unexpected adverse events. PVC tubing burst between 36 and 78 hours, while silicon tubing lasted for at least 7 days. At 7 days, the silicone tubing showed significant signs of roller pump wear visible on the outside. The inside, however, was free of surface irregularities. Using these tubings in a roller pump led to a remarkable increase in circuit temperature (PVC: +12.0°C, silicone +2.9°C). Kinking or suction on the device caused the expected dramatic flow reduction (as assessed by direct measurement) while the roller pump display continued to show the preset flow. The roller pump is therefore not able to reliably determine the true flow rate. Conclusion: Roller pumps with silicone tubing but not PVC tubing may be used for running ECMO circuits. Silicone tubing may endure the roller pump shear forces for up to 1 week. Thus, repeated tubing repositioning may be a solution. Circuit heating and substantial limitations in flow detection should increase attention if clinical use in situations of crisis is considered.

Pump Performance Improvement by Restraining Back Flow in Screw-Type Centrifugal Pump

2005 ◽  
Vol 127 (4) ◽  
pp. 755-762 ◽  
Author(s):  
Yasushi Tatebayashi ◽  
Kazuhiro Tanaka ◽  
Toshio Kobayashi
Keyword(s):  
Pressure Fluctuations ◽  
Centrifugal Pumps ◽  
Two Phase ◽  
Simple Method ◽  
Back Flow ◽  
Pump Performance ◽  
Impeller Outlet ◽  
Pump Head ◽  
The Difference ◽  
Set Up

The authors have been investigating the various characteristics of screw-type centrifugal pumps, such as pressure fluctuations in impellers, flow patterns in volute casings, and pump performance in air-water two-phase flow conditions. During these investigations, numerical results of our investigations made it clear that three back flow regions existed in this type of pump. Among these, the back flow from the volute casing toward the impeller outlet was the most influential on the pump performance. Thus the most important factor to achieve higher pump performance was to reduce the influence of this back flow. One simple method was proposed to obtain the restraint of back flow and so as to improve the pump performance. This method was to set up a ringlike wall at the suction cover casing between the impeller outlet and the volute casing. Its effects on the flow pattern and the pump performance have been discussed and clarified to compare the calculated results with experimental results done under two conditions, namely, one with and one without this ring-type wall. The influence of wall’s height on the pump head was investigated by numerical simulations. In addition, the difference due to the wall’s effect was clarified to compare its effects on two kinds of volute casing. From the results obtained it can be said that restraining the back flow of such pumps was very important to achieve higher pump performance. Furthermore, another method was suggested to restrain back flow effectively. This method was to attach a wall at the trailing edge of impeller. This method was very useful for avoiding the congestion of solids because this wall was smaller than that used in the first method. The influence of these factors on the pump performance was also discussed by comparing simulated calculations with actual experiments.

Analysis of Blunt Trailing Edge Airfoils

2003 ◽  
Author(s):  
K. J. Standish ◽  
C. P. van Dam
Keyword(s):  
Experimental Data ◽  
Wind Turbine ◽  
Turbine Blades ◽  
Navier Stokes ◽  
Computational Techniques ◽  
Wind Turbine Blades ◽  
Trailing Edge ◽  
Blunt Trailing Edge ◽  
Large Wind ◽  
Structural Volume

The adoption of blunt trailing edge airfoils for the inner regions of large wind turbine blades has been proposed. Blunt trailing edge airfoils would not only provide increased structural volume, but have also been found to improve the lift characteristics of airfoils and therefore allow for section shapes with a greater maximum thickness. Limited experimental data makes it difficult for wind turbine designers to consider and conduct tradeoff studies using these section shapes. This lack of experimental data precipitated the present analysis of blunt trailing edge airfoils using computational fluid dynamics. Several computational techniques are applied including a viscous/inviscid interaction method and several Reynolds-averaged Navier-Stokes methods.

scholarly journals Effects of an Ex Vivo Pediatric Extracorporeal Membrane Oxygenation Circuit on the Sequestration of Mycophenolate Mofetil, Tacrolimus, Hydromorphone, and Fentanyl

2019 ◽  
Vol 24 (4) ◽  
pp. 290-295
Author(s):  
Catherine S. Heith ◽  
Lizbeth A. Hansen ◽  
Rhonda M. Bakken ◽  
Sharon L. Ritter ◽  
Breeanna R. Long ◽  
...  
Keyword(s):  
Mycophenolate Mofetil ◽  
Extracorporeal Membrane Oxygenation ◽  
Mycophenolic Acid ◽  
Pediatric Patients ◽  
Ex Vivo ◽  
Centrifugal Pumps ◽  
Ecmo Circuit ◽  
Binding Characteristics ◽  
Membrane Oxygenation ◽  
Set Up

OBJECTIVES With the expanding use of extracorporeal membrane oxygenation (ECMO), understanding drug pharmacokinetics has become increasingly important, particularly in pediatric patients. This ex vivo study examines the effect of a pediatric Quadrox-iD ECMO circuit on the sequestration and binding of mycophenolate mofetil (MMF), tacrolimus, and hydromorphone hydrochloride, which have not been extensively studied to date in pediatric ECMO circuits. Fentanyl, which has been well studied, was used as a comparator. METHODS ECMO circuits were set up using Quadrox-iD pediatric oxygenators and centrifugal pumps. The circuit was primed with whole blood and a reservoir was attached to represent a 5-kg patient. Fourteen French venous and 12 French arterial ECMO cannulas were inserted into the sealed reservoir. Temperature, pH, PO2, and PCO2 were monitored and corrected. MMF, tacrolimus, hydromorphone, and fentanyl were injected into the ECMO circuit. Serial blood samples were taken from a postoxygenator site at intervals over 12 hours, and levels were measured. RESULTS Hydromorphone hydrochloride was not as significantly sequestered by the ex vivo pediatric ECMO circuit when compared with fentanyl. Both mycophenolic acid and tacrolimus serum concentrations were stable in the circuit over 12 hours. CONCLUSIONS Hydromorphone may represent a useful medication for pain control for pediatric patients on ECMO due to its minimal sequestration. Mycophenolic acid and tacrolimus also did not show significant sequestration in the circuit, which was unexpected given their lipophilicity and protein-binding characteristics, but may provide insight into unexplored pharmacokinetics of particular medications in ECMO circuits.

Pump Performance Improvement by Restraining Back Flow in Screw-Type Centrifugal Pump

2005 ◽  
Author(s):  
Yasushi Tatebayashi ◽  
Kazuhiro Tanaka ◽  
Toshio Kobayashi
Keyword(s):  
Pressure Fluctuations ◽  
Centrifugal Pumps ◽  
Two Phase ◽  
Simple Method ◽  
Back Flow ◽  
Pump Performance ◽  
Impeller Outlet ◽  
Pump Head ◽  
The Difference ◽  
Set Up

The authors have been investigating the various characteristics of screw-type centrifugal pumps, such as pressure fluctuations in impellers, flow patterns in volute casings, and pump performance in air-water two-phase flow conditions. During these investigations, numerical results of our investigations made it clear that three back flow regions existed in this type of pump. Among these, the back flow from the volute casing toward the impeller outlet was the most influential on the pump performance. Thus the most important factor to achieve higher pump performance was to reduce the influence of this back flow. One simple method was proposed to obtain the restraint of back flow and so as to improve the pump performance. This method was to set up a Ring-like wall at the suction cover casing between the impeller outlet and the volute casing. Its effects on the flow pattern and the pump performance have been discussed and clarified to compare the calculated results with experimental results done under two conditions — namely, one with and one without this Ring-type wall. The influence of wall’s height on the pump head was investigated by numerical simulations. In addition, the difference due to the wall’s effect was clarified to compare its effects on two kinds of volute casing. From the results obtained it can be said that restraining the back flow of such pumps was very important to achieve higher pump performance. Furthermore, another method was suggested to restrain back-flow effectively. This method was to attach a wall at the trailing edge of impeller. This method was very useful for avoiding the congestion of solids because this wall was smaller than that used in the first method. The influence of these factors on the pump performance was also discussed by comparing simulated calculations with actual experiments.

Evaluating the Performance Degradation of Centrifugal Pumps Using the Principal Component Analysis

2021 ◽  
Author(s):  
Andrew Eaton ◽  
Wael Ahmed ◽  
Marwan A. Hassan
Keyword(s):  
Principal Component Analysis ◽  
Distribution Systems ◽  
Water Distribution ◽  
Principal Component ◽  
Component Analysis ◽  
Performance Degradation ◽  
Centrifugal Pumps ◽  
Pump Performance ◽  
Hydraulic Machines ◽  
Wide Range

Abstract Centrifugal pumps are used in a variety of engineering applications, such as power production, heating, cooling, and water distribution systems. Although centrifugal pumps are considered to be highly reliable hydraulic machines, they are susceptible to a wide range of damage due to several degradation mechanisms, which make them operate away from their best efficiency range. Therefore, evaluating the energy efficiency and performance degradation of pumps is an important consideration to the operation of these systems. In the present study, the hydraulic performance along with the vibration response of an industrial scale centrifugal pump (7.5KW) subjected to different levels of impeller unbalance were experimentally investigated. Extensive testing of pump performance along with vibration measurements were carried. Both time and frequency domain techniques coupled with principal component analysis (PCA) were used in this evaluation. The effect of unbalance on the pump performance was found to be mainly on the shaft power, while no change in the flow rate and the pump head were observed. As the level of unbalance increased, the power required to operate the pump at the designated speed increased by as much as 12%. The PCA found to be a useful tool in comparing the pump vibrations in the field in order to determine the presence of unbalance as well as the degree of damage. The results of this work can be used to evaluate and monitor pump performance under prescribed degradation in order to enhance preventative maintenance programs.

Characterization of a Newly Designed Test Bench for Investigations of Flame-Wall-Interaction

2021 ◽  
Author(s):  
Rahand Dalshad ◽  
Tobias Sander ◽  
Michael Pfitzner
Keyword(s):  
Test Bench ◽  
Turbine Blades ◽  
Thermal Design ◽  
Optical Methods ◽  
Detailed Knowledge ◽  
Combustion Chambers ◽  
First Results ◽  
Wall Interaction ◽  
Set Up ◽  
Near Wall

Abstract For the thermal design of combustion chambers and turbine blades in jet engines, a detailed knowledge of the combustion and of the heat loads to the walls is necessary. In general, high operating temperatures and reduced combustor size are striven for in order to increase engine efficiency and reduce weight. Consequently, the components are exposed to temperatures above the melting point of the materials and there is a growing risk of incomplete combustion within the combustion chambers. To study these effects, we set up a new test bench for fundamental investigation of chemical near-wall reactions at atmospheric pressure. First results of gaseous, non-premixed near-wall CH4/air and H2/air flames are presented. Optical methods such as two-line laser-induced fluorescence thermometry and OH* chemiluminescence were applied. Further, the heat release to the wall was determined by means of inverse heat conduction calculation using the data of implemented thermocouples.

The Measurement of Stress and Vibration Data in Turbine Blades and Aeroengine Components

1988 ◽  
Author(s):  
D. E. Oliver ◽  
D. J. Berry
Keyword(s):  
Computer Aided Design ◽  
Turbine Blades ◽  
Thermoelastic Effect ◽  
Full Field ◽  
Experimental Stress Analysis ◽  
Vibration Data ◽  
Set Up ◽  
Stress Measuring ◽  
Aided Design ◽  
Aeroengine Components

Instrumentation utilizing the thermoelastic effect has become established in recent years as an important tool for experimental stress analysis. This instrumentation provides full field stress data in a digitized form that can be integrated with computer aided design methods for experimental optimization and validation of designs. More recently the same full field data acquisition techniques have been applied to vibration measurements. As a result stress and vibration data can be obtained from the same experimental set-up. The paper describes theoretical aspects of the thermoelastic effect upon which the stress measurements are based. It goes on to show how laser Doppler interferometric techniques can be incorporated into stress measuring instrumentation. Results from typical aerospace components are used to illustrate applications of commercially available instrumentation (Fig. 1).

Improving the Performance of Centrifugal Pumps in Serial and Parallel Configurations Using Digital Twins

2019 ◽  
Author(s):  
Andrés L. Carrillo Peña ◽  
Jeffer S. Eugenio Barroso ◽  
Alberto A. Martínez Vesga ◽  
Sebastián Roa Prada ◽  
Victor A. Ardila Acuña
Keyword(s):  
Experimental Data ◽  
Operating Conditions ◽  
Water Supply Systems ◽  
Strong Impact ◽  
Simulation Environment ◽  
Centrifugal Pumps ◽  
Digital Twin ◽  
Pumping System ◽  
Digital Twins ◽  
Hydraulic Machines

Abstract Centrifugal pumps are devices commonly used in countless industrial and residential applications, from water supply systems to oil and gas processing plants. These rotatory hydraulic machines have a strong impact on the energy consumption of industry worldwide, not only because of their vast amount but also because of their continuous operation. Therefore, developing techniques to improve the efficiency of pumping systems is of great help to make communities and industrial activity more sustainable. The overall performance of these pieces of machinery cannot be fully predicted by means of analytical procedures due to the complexity of the fluid flow phenomena that occurs in their interior, so it is common practice to resort to alternate modeling techniques, such as computer aided numerical analysis, which can predict the performance of a pump, given its CAD computer model. However, the performance of an actual centrifugal pump may deviate from its ideal behavior due to multiple causing factors which may alter the performance curves given by the manufacturers in the corresponding data sheets. The discrepancies between the real and the simulated responses of centrifugal pumps demand for better modeling and simulation techniques to improve the design of more efficient pumping systems. Digital twins have the ability to bring the simulation environment closer to reality, by replicating the behavior of the physical system in a simulation environment with the support of experimental data. The digital twin of a multiple pumps system with serial and parallel configurations was developed, based on two identical industrial centrifugal pumps available in the laboratory. Experimental data was collected to calibrate the digital twin system so that the simulated system can predict the response under changing operating conditions. The simulation environment was developed with the assistance of a commercial Computational Fluid Dynamics computer program. After validating the behavior of the virtual components, with respect to the behavior of their actual counterparts, tests were carried out to predict the behavior of the pumping system in case of downstream disturbances which can affect the operating point of the overall pumping system and its corresponding efficiency. The development of the digital twin for the pumping system allowed visualizing how the pumps connected in series or in parallel can be maneuvered to adjust its operating conditions to achieve higher efficiency operating conditions in response to changes in the conditions downstream in the pipeline.

scholarly journals Flutter Mechanisms in Low Pressure Turbine Blades

1998 ◽  
Author(s):  
M. Nowinski ◽  
J. Panovsky
Keyword(s):  
Research Effort ◽  
Turbine Blades ◽  
Low Pressure ◽  
Design Parameters ◽  
Computational Techniques ◽  
Influence Coefficient ◽  
Low Pressure Turbine ◽  
Blade Flutter ◽  
Euler Methods ◽  
Annular Cascade

The work described in this paper is part of a comprehensive research effort aimed at eliminating the occurrence of low pressure turbine blade flutter in aircraft engines. The results of fundamental unsteady aerodynamic experiments conducted in an annular cascade are studied in order to improve the overall understanding of the flutter mechanism and to identify the key flutter parameters. In addition to the standard traveling wave tests, several other unique experiments are described. The influence coefficient technique is experimentally verified for this class of blades. The beneficial stabilizing effect of mistuning is also directly demonstrated. Finally, the key design parameters for flutter in low pressure turbine blades are identified. In addition to the experimental effort, correlating analyses utilizing linearized Euler methods demonstrate that these computational techniques are adequate to predict turbine flutter.

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